The Nobel Prize in Physiology or Medicine 2015 has been awarded to three scientists for discoveries that have transformed treatment of malaria and a few other parasitic diseases, which afflict hundreds of millions of people each year.

The drug discovered by Campbell and Omura is used to control parasites in dogs, horses and other livestock.

“Professor Campbell was centrally involved in developing the cure against river blindness”, said Patrick Prendergast, the Provost of Trinity College Dublin welcoming the announcement.

Undated file photo shows Tu Youyou, a pharmacologist with the China Academy of Chinese Medical Sciences, working to make artemisinin, a drug therapy for malaria, in 1980s.

Close to 100 million Mectizan prescriptions are given across the globe each year, and the drug has led to the local eradication of worm-borne diseases, like river blindness, in much of South America and parts of Africa.

Lymphatic filariasis, another parasitic disease, is spread by the bites of infected mosquitoes. Still, more than 450,000 people die annually from malaria, according to the Nobel Committee’s statement. He traveled around Japan collecting soil samples in the hopes of finding a natural product to combat disease-causing microbes.

Omura is a Japanese microbiologist who isolated 50 of the most promising strains of Streptomyces for use against harmful agents. The substance was purified and named Avermectin.

The bioactive agent avermectin, was chemically modified to a more effective compound called ivermectin and marketed as a drug by pharmaceutical giant Merck (Merck Sharpe and Dohme).

Omura, an 80-year-old professor emeritus at Kitasato University in Japan, and his colleague William Campbell, 85, an Ireland-born research fellow emeritus at Drew University in the United States, shared the prize for their discovery of a new drug, Avermectin.

In 2011 we took a look at Professor Youyou Tu’s research that led to the development of Artemisinin therapy for malaria, and the key role played by mouse models of malaria infection, in a post entitled “George is OK: Thank the men who stare down microscopes!”

Ge Hong, a fourth-century physician, alchemist and herbalist, wrote a “handbook of prescriptions for emergencies” in 340AD that included a key passage on how to treat malaria with an extract made from the sweet wormwood shrub, Artemisia annua. “Campbell acquired Omura”s cultures and conducted extensive tests on farm and domestic animals. She discovered artemisinin, which has been used by millions against malaria. It has reduced overall mortality rates from the disease by 20 percent. “So it as very exciting to see that develop from the initial discovery that Omura made into a product that has now saved many thousands of lives, particularly in Africa”.

Nobel Assembly at the Karolinska Institute “After decades of limited progress in developing durable therapies for parasitic diseases, the discoveries by this year’s laureates radically changed the situation”, says the Nobel Assembly at the Karolinska Institute, which selects Nobel Prize winners in physiology or medicine.